he cat tribe because the kitten is accustomed to
imitate cats; when it falls to playing it is with cats, and so it
sheds its superfluous energies in the customary imitative channels. In
this way it grows to learn the games of its own species. There is a
good deal in this point; most games are imitative in so far as they
are learned at all. But it does not save the theory; for many animal
plays are not learned by the individual at all, as we have seen above;
on the contrary, they are instinctive. In these cases the animal does
not wait to learn the games of his tribe by imitation, but
starts-right-in on his own account. Besides this there are many forms
of animal play which are not imitative at all. In these the animals
co-operate, but do not take the same parts. The young perform actions
in the game which the mother does not.

All this goes to support another and most serious objection to this
theory--in the mind of all those who believe in the doctrine of
evolution. The Surplus-Energy Theory considers the play-impulse, which
is one of the most widespread characters of animal life, as merely an
accidental thing or by-product--a mere using-up of surplus energies.
It is not in any way important to the animals. This makes it
impossible to say that play has come to be the very complex thing that
it really is by the laws of evolution; for survival by natural
selection always supposes that the attribute or character which
survives is important enough to keep the animal alive in the struggle
for existence; otherwise it would not be continued for successive
generations, and gradually perfected on account of its utility.

On the whole, therefore, we find the Surplus-Energy Theory of play
quite inadequate.

II. Another theory therefore becomes necessary if we are to meet these
difficulties. Such a theory has recently been developed. It holds that
the plays of the animals are of the greatest utility to them in this
way: they exercise the young animals in the very activities--though in
a playful way--in which they must seriously engage later on in life. A
survey of the plays of animals with a view to comparing them in each
case with the adult activities of the same species, confirms this
theory in a remarkably large number of cases. It shows the young
anticipating, in their play, the struggles, enjoyments, co-operations,
defeats, emergencies, etc., of their after lives, and by learning to
cope with all these situations, so prepa